We use as source for the globular cluster photometry the compilation of ACS/WFC F606W/F814W photometry published by [1]} as well the HST photometry that was derived in [2]},
[3]} and [4]}. We also use the photometry published by [5]} for NGC 6626 as input photometry.
We exclude NGC 5139 from this list due to the significant metallicity spread among the cluster stars.
For each HST observation, we again fit PARSEC isochrones [6]} to the cluster color-magnitude diagrams. To create the isochrones, we use the cluster ages derived
by [7]}, or, for clusters not studied by them, from available literature sources,
and take the cluster metallicities and reddenings from [8]}. From the isochrones we then derive individual stellar masses for the main-sequence stars in the clusters.
We fit the \(N\) -body models of [9]} and [10]} to the observed surface density, velocity dispersion profiles and the observed mass function of main sequence stars in the
HST fields and determine the best-fitting \(N\) -body model from the fit. For each HST observation, we fit a power-law mass function \(N(m) \sim m^{\alpha }\)  to the observed stellar mass distribution as well as the
masses of stars in the \(N\) -body models in the same field. We use the mass function slopes \(\alpha \)  as fit parameters but not the absolute number of stars. Fig. REF  shows as an example the distribution of
HST fields with measured photometry (left panel), the derived color-magnitude diagram (middle panel), and the measured stellar mass functions at different distances from the centre (right panel) for the globular cluster NGC 104.
